[tor-bugs] #21311 [Core Tor/Tor]: launch_resolve() should always resolve AAAA records, regardless of IPv6Exit

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#21311: launch_resolve() should always resolve AAAA records, regardless of IPv6Exit
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 Reporter:  teor          |          Owner:
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Milestone:  Tor: unspecified
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:  ipv6          |  Actual Points:
Parent ID:                |         Points:  1
 Reviewer:                |        Sponsor:
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Comment (by arma):

 Right. Specifically, it's this code:
 {{{
     if (get_options()->IPv6Exit)
 }}}

 The underlying bug is that exit relays are returning REASON_RESOLVEFAILED
 for resolve attempts to addresses like ipv6.google.com, which causes
 clients to get no hints about which exits might be able to reach that
 address successfully. If the exit relay would do the AAAA resolve, then it
 could usefully respond with REASON_EXITPOLICY, and include the v6 address
 in the end cell, and then clients could try again on a circuit that has
 explicit v6 exit support.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21311#comment:2>
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